DO NOT USE

upon further review of how SEO operates I have found this plugin to not only be worthless, but counter-productive.

There are numerous problems beyond this by I will quickly try to summarize:
It repeats the content as the page description, search engines consider this a content injection. If the post’s summary is set to be different content such as a teaser then it works fine.

The keywords of the homepage are the currently displayed article. Your homepage is not 1 article (usually), the homepage keywords should be the sites focus or ideals. When the homepage’s keywords are changed with the next post, the pagerank is reduced. However, this feature on individual article pages is great (as the keywords remain the same).

It sets the canonical to be the current url The canonical is supposed to be the permanent url of the content when the content is being temporarily featured. It is never supposed to be the current url (redundant, bad).
The homepage declaring itself to be the canonical of the content tells search engines the content is intentionally duplicated, to remain (very bad).
When the homepage changes to the next post, a page declaring to be canonical is changing its content (very bad).
The article’s pagerank is reduced because the content is duplicated else where (bad).

A proper SEO pack will set the canonical only on the homepage, to be the url of the content featured, it will set the keywords on the homepage to be the keywords of the site while the keywords on post pages to be the posts topics, and it will not whole-chunk duplicate the page’s content as the description.

With current search engine practices, this plugin currently causes more harm than benefits.

If you need/want to use it and don’t mind modifying code, simply delete the line that echos the canonical tag and much of its deficiencies are resolved.